Some firefighters unaccounted for after blast

In this Instagram photo provided by Andy Bartee, a plume of smoke rises from a fertilizer plant fire in West, Texas on Wednesday, April 17, 2013. An explosion at a fertilizer plant near Waco Wednesday night injured dozens of people and sent flames shooting high into the night sky, leaving the factory a smoldering ruin and causing major damage to surrounding buildings. (AP Photo/Andy Bartee) MANDATORY CREDIT: ANDY BARTEE
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In this Instagram photo provided by Andy Bartee, a plume of smoke rises from a fertilizer plant fire in West, Texas on Wednesday, April 17, 2013. An explosion at a fertilizer plant near Waco Wednesday night injured dozens of people and sent flames shooting high into the night sky, leaving the factory a smoldering ruin and causing major damage to surrounding buildings. (AP Photo/Andy Bartee) MANDATORY CREDIT: ANDY BARTEE
/ AP

Elderly persons from a nearby nursing home are triaged in a parking lot before being moved to a school stadium following a fertilizer plant explosion Wednesday, April 17, 2013, in West, Texas. The explosion near Waco Wednesday night injured dozens of people and sent flames shooting high into the night sky, leaving the factory a smoldering ruin and causing major damage to surrounding buildings. (AP Photo/Waco Tribune Herald, Rod Aydelotte)— AP

Elderly persons from a nearby nursing home are triaged in a parking lot before being moved to a school stadium following a fertilizer plant explosion Wednesday, April 17, 2013, in West, Texas. The explosion near Waco Wednesday night injured dozens of people and sent flames shooting high into the night sky, leaving the factory a smoldering ruin and causing major damage to surrounding buildings. (AP Photo/Waco Tribune Herald, Rod Aydelotte)
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Persons are seen pushing wheel chairs in front of a damaged nursing home following an explosion at a nearby fertilizer plant Wednesday, April 17, 2013, in West, Texas. An explosion at a fertilizer plant near Waco caused numerous injuries and sent flames shooting high into the night sky on Wednesday.(AP Photo/ Waco Tribune Herald, Rod Aydelotte)— AP

Persons are seen pushing wheel chairs in front of a damaged nursing home following an explosion at a nearby fertilizer plant Wednesday, April 17, 2013, in West, Texas. An explosion at a fertilizer plant near Waco caused numerous injuries and sent flames shooting high into the night sky on Wednesday.(AP Photo/ Waco Tribune Herald, Rod Aydelotte)
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Emergency workers evacuate elderly from a damaged nursing home following an explosion at a fertilizer plant Wednesday, April 17, 2013, in West, Texas. An explosion at a fertilizer plant near Waco caused numerous injuries and sent flames shooting high into the night sky on Wednesday. (AP Photo/ Waco Tribune Herald, Rod Aydelotte)— AP

Emergency workers evacuate elderly from a damaged nursing home following an explosion at a fertilizer plant Wednesday, April 17, 2013, in West, Texas. An explosion at a fertilizer plant near Waco caused numerous injuries and sent flames shooting high into the night sky on Wednesday. (AP Photo/ Waco Tribune Herald, Rod Aydelotte)
/ AP

Emergency workers assist an elderly person at a staging area at a local school stadium Wednesday, April 17, 2013, in West, Texas. An explosion Wednesday night at a fertilizer plant near Waco sent flames shooting high into the night sky, leaving the factory a smoldering ruin, causing major damage at nearby buildings and injuring numerous people. (AP Photo/Waco Tribune Herald, Rod Aydelotte)— AP

Emergency workers assist an elderly person at a staging area at a local school stadium Wednesday, April 17, 2013, in West, Texas. An explosion Wednesday night at a fertilizer plant near Waco sent flames shooting high into the night sky, leaving the factory a smoldering ruin, causing major damage at nearby buildings and injuring numerous people. (AP Photo/Waco Tribune Herald, Rod Aydelotte)
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An elderly person is assisted at a staging area at a local school stadium following an explosion at a fertilizer plant Wednesday, April 17, 2013, in West, Texas. An explosion at a fertilizer plant near Waco caused numerous injuries and sent flames shooting high into the night sky on Wednesday. (AP Photo/ Waco Tribune Herald, Rod Aydelotte)— AP

An elderly person is assisted at a staging area at a local school stadium following an explosion at a fertilizer plant Wednesday, April 17, 2013, in West, Texas. An explosion at a fertilizer plant near Waco caused numerous injuries and sent flames shooting high into the night sky on Wednesday. (AP Photo/ Waco Tribune Herald, Rod Aydelotte)
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A person looks on as emergency workers fight a house fire after a nearby fertilizer plant exploded Wednesday, April 17, 2013, in West, Texas. A massive explosion at the fertilizer plant near Waco on Wednesday night injured dozens of people and sent flames shooting into the night sky, leaving the factory a smoldering ruin following a blast that damaged buildings for blocks in every direction. (AP Photo/Waco Tribune Herald, Rod Aydelotte)— AP

A person looks on as emergency workers fight a house fire after a nearby fertilizer plant exploded Wednesday, April 17, 2013, in West, Texas. A massive explosion at the fertilizer plant near Waco on Wednesday night injured dozens of people and sent flames shooting into the night sky, leaving the factory a smoldering ruin following a blast that damaged buildings for blocks in every direction. (AP Photo/Waco Tribune Herald, Rod Aydelotte)
/ AP

WEST, Texas 
The mayor of a Texas town where a fertilizer plant explosion injured more than 100 people says some firefighters who were battling a blaze when the blast happened aren't accounted for.

West Mayor Tommy Muska says there were five or six volunteer firefighters battling the blaze at the West Fertilizer plant when the explosion happened just before 8 p.m. Wednesday.

Muska, who is a volunteer firefighter himself, says not all of his fellow firefighters are accounted for. He says the blast knocked his helmet off and shattered the windows of his nearby home.

Authorities say an unknown number of people were killed in the blast, which leveled buildings for blocks in every direction.